Organic Chemistry – Some Basic Principles and Techniques

In which of the following molecules, atoms are coplanar?

1. [figure]
2. [figure]
3. [figure]
4. [figure]

In pyrrole the electron density is maximum on [figure]

1. 2 and 3
2. 3 and 4
3. 2 and 4
4. 2 and 5

Which of the following statements is not correct for a nucleophile?

1. Ammonia is a nucleophile.
2. Nucleophiles attack low e- density sites.
3. Nucleophiles are not electron seeking.
4. Nucleophile is a Lewis acid.

The total number of π-bond electrons in the following structure is [figure]

1. 12
2. 16
3. 4
4. 8

Which of the following is the most correct electron displacement for a nucleophilic reaction to take place?

1. [figure]
2. [figure]
3. [figure]
4. [figure]

Consider the following compounds : [figure] Hyperconjugation occurs in

1. III only
2. I and III
3. I only
4. II only

The enolic form of ethyl acetoacetate as shown below has [figure]

1. 9 sigma bonds and 2 pi-bonds
2. 9 sigma bonds and 1 pi-bond
3. 18 sigma bonds and 2 pi-bonds
4. 16 sigma bonds and 1 pi-bond.

In which of the following compounds, the C–Cl bond ionisation shall give most stable carbonium ion?

1. [figure]
2. [figure]
3. [figure]
4. [figure]

Given : [figure] The enthalpy of hydrogenation of these compounds will be in the order as

1. II > III > I
2. II > I > III
3. I > II > III
4. III > II > I

Which of the following organic compounds has same hybridization as its combustion product (CO2)?

1. Ethane
2. Ethyne
3. Ethene
4. Ethanol